The Power Rating of a Skill Roll is an additional die(dice) that is/are rolled and added to the number of Successes gained in a normal Skill check, but only if the Skill check gains at least one success.

The purpose of Power is to differentiate between precision and strength. A ballet dancer can leap using great skill, while a weight lifter leaps with great force. The dancer has a great chance of leaping accurately, but may not have the force to clear much space. The weight lifter may have the power to clear a great deal of space in a leap, but may waste that power by flinging themselves ungracefully into a wall.